Processing, natural gas

Olefins are produced primarily by thermal cracking of a hydrocarbon feedstock which takes place at low residence time in the presence of steam in the tubes of a furnace. In the United States, natural gas Hquids derived from natural gas processing, primarily ethane [74-84-0] and propane [74-98-6] have been the dominant feedstock for olefins plants, accounting for about 50 to 70% of ethylene production. Most of the remainder has been based on cracking naphtha or gas oil hydrocarbon streams which are derived from cmde oil. Naphtha is a hydrocarbon fraction boiling between 40 and 170°C, whereas the gas oil fraction bods between about 310 and 490°C. These feedstocks, which have been used primarily by producers with refinery affiliations, account for most of the remainder of olefins production. In addition a substantial amount of propylene and a small amount of ethylene ate recovered from waste gases produced in petroleum refineries. 

In 1991, there were approximately 418 sulfur production plants associated with oil and gas production in operation throughout the world. Approximately 86% of these plants were based on the Claus process, and there were 118 Claus units operating in natural gas processing faciHties (11). 

Butanes are naturally occurring alkane hydrocarbons that are produced primarily in association with natural gas processing and certain refinery operations such as catalytic cracking and catalytic reforming. The term butanes includes the two stmctural isomers, / -butane [106-97-8] CH2CH2CH2CH2, and isobutane [79-28-9], (CH2)2CHCH2 (2-methylpropane). 

Other natural gas Hquids include natural gasoline [8006-61 -9] which is composed of the pentanes and heavier components of the natural gas stream, and ethane [74-84-0]. Most recendy ethane has become the principal product of natural gas processing plants. 

Historically, about two-thirds of the LPG produced in the United States came from natural gas processing and one-third was produced from refinery operations (2). In 1991, this ratio was 61% from natural gas processing and 39% from refinery operations. Total production of LPG in 1991 was 76.85 X 10 m (294.19 x 10 bbl) from natural gas processing and 30.08 x 10 m (189.23 x 10 bbl) produced from refinery operations. 

Design and Construction ofiEP-Gas Installations at Marine Terminals, Natural Gas Processing Plants, Refineries, Petrochemical Plants, and Tank Farms, API Standard 2510, 4th ed., American Petroleum Institute, Washington, D.C., Dec. 1978. 

J. N. Robiason, "Estimation of the Water Content of Sour Natural Gas," presented at Canadian Natural Gas Processing Association, Calgary, Alberta,... 

The need to obtain greater recoveries of the C9, C3, and C4S in natural gas has resulted in the expanded use of low-temperature processing of these streams. The majority of the natural gas processing at low temperatures to recover light hydrocarbons is now accomphshed using the turboexpander cycle. Feed gas is normally available from 1 to 10 MPa. The gas is first dehydrated to a dew point of 200 K and lower. After dehydration the feed is cooled with cold residue gas. Liquid produced at this point is separated before entering the expander and sent to the condensate stabilizer. The gas from the separator is... 

Equipment Leaks of VOG from Onshore Natural Gas Processing Plants... 

The hfe of a gas turbine depends heavily on the type of fuel used. An inherent fuel flexibility is the gas turbines major advantage. Gaseous fuels traditionaUy include natural gas, process gas, and low-Btu gas... 

As stated earlier, turboexpanders are normally used in cryogenic processes to produce isentropic expansion to cool down the process gas. Two common applications are natural gas processing plants and chemical plants. In natural gas processing plants, turboexpanders are installed to liquify heavier hydrocarbon components and produce lean natural gas with specified dew point limits to meet required standards. 

In chemical plants, turboexpanders are used to produce refrigeration for cold box installations. In all except energy recovery applications, there are gas-to-gas heat exchangers downstream of the turboexpander. Figure 6-14 recaps a process flow diagram of a natural gas processing gas plant. 

Figure 6-14. Process flow diagram of a typical natural gas processing plant.

Natural Gas Processing and Hydrocarbon Separation, Mehra Process, Encyclopedia of Chemical Processing and Design, McKetta, Editor, Marcel Dekker. Vol. 31, p. 35. 

See also Biofuels Capital Investment Decisions Hydrogen Kinetic Energy, Historical Evolution of the Use of Methanol Natural Gas, Processing and Conversion of. 

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